Fix language and formatting in ChangeLog

Changed the formatting and language in the ChangeLog to the house-style.
diff --git a/ChangeLog b/ChangeLog
index b9d3a72..d70d19a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,13 +3,23 @@
 = mbed TLS x.x.x branch released xxxx-xx-xx
 
 Security
-   * Fix overly strict DN comparison when looking for CRLs
-     belonging to a particular CA. This previously lead to
-     ignoring CRLs when the CRL's issuer name and the CA's
-     subject name differed in their string encoding (e.g.,
-     one using PrintableString and the other UTF8String) or
-     in the choice of upper and lower case. Reported by
-     HenrikRosenquistAndersson in #1784.
+   * Fix overly strict DN comparison when looking for CRLs belonging to a
+     particular CA. This previously lead to ignoring CRLs when the CRL's issuer
+     name and the CA's subject name differed in their string encoding (e.g.,
+     one using PrintableString and the other UTF8String) or in the choice of
+     upper and lower case. Reported by Henrik Andersson of Bosch GmbH in issue
+     #1784.
+   * Fix mbedtls_mpi_is_prime() to use more rounds of probabilistic testing. The
+     previous settings for the number of rounds made it practical for an
+     adversary to construct non-primes that would be erroneously accepted as
+     primes with high probability. This does not have an impact on the
+     security of TLS, but can matter in other contexts with potentially
+     adversarially-chosen numbers that should be prime and can be validated.
+     For example, the number of rounds was enough to securely generate RSA key
+     pairs or Diffie-Hellman parameters, but was insufficient to validate
+     Diffie-Hellman parameters properly.
+     See "Prime and Prejudice" by by Martin R. Albrecht and Jake Massimo and
+     Kenneth G. Paterson and Juraj Somorovsky.
    * Fix a flawed bounds check in server PSK hint parsing. In case the
      incoming message buffer was placed within the first 64KB of address
      space and a PSK-(EC)DHE ciphersuite was used, this allowed an attacker
@@ -30,8 +40,8 @@
      Fixes #2069.
    * Fix memory leak and freeing without initialization in the example
      program programs/x509/cert_write. Fixes #1422.
-   * Ignore iv in mbedtls_cipher_set_iv() when the cipher mode is MBEDTLS_MODE_ECB
-     Fix for #1091 raised by ezdevelop
+   * Ignore IV in mbedtls_cipher_set_iv() when the cipher mode is
+     MBEDTLS_MODE_ECB. Found by ezdevelop. Fixes for #1091.
    * Zeroize memory used for reassembling handshake messages after use.
    * Use `mbedtls_zeroize()` instead of `memset()` for zeroization of
      sensitive data in the example programs aescrypt2 and crypt_and_hash.
@@ -53,19 +63,6 @@
    * Improve documentation of mbedtls_ssl_get_verify_result().
      Fixes #517 reported by github-monoculture.
 
-Security
-   * Fix mbedtls_mpi_is_prime() to use more rounds of probabilistic testing. The
-     previous settings for the number of rounds made it practical for an
-     adversary to construct non-primes that would be erroneously accepted as
-     primes with high probability. This does not have an impact on the
-     security of TLS, but can matter in other contexts with potentially
-     adversarially-chosen numbers that should be prime and can be validated.
-     For example, the number of rounds was enough to securely generate RSA key
-     pairs or Diffie-Hellman parameters, but was insufficient to validate
-     Diffie-Hellman parameters properly.
-     See "Prime and Prejudice" by by Martin R. Albrecht and Jake Massimo and
-     Kenneth G. Paterson and Juraj Somorovsky.
-
 = mbed TLS 2.7.6 branch released 2018-08-31
 
 Security